A technology industry urban legend claims that Kildall went flying rather than meet with IBM, thus causing IBM to market Microsoft's inferior operating system, changing the course of computer history. The story is untrue.

Photos: (left) Mickey Phleger; (right) WGBH

PC Software

A West Coast pioneer wrote the first software for a microprocessor, and then created a disk operating system for it. His creations for the personal computer underlie every desktop or laptop system in use today.

From Math to Computers
The descendent of Norwegian immigrants who ran a school for nautical navigation, Kildall was born in 1942. He was an indifferent student who liked to spend his time rebuilding old cars, but he attended the University of Washington in his hometown of Seattle, planning to become a math teacher. Instead, he became fascinated with computers -- at that time, mostly mainframe devices that occupied whole rooms and were programmed with punch cards. He would eventually earn a Ph.D. in the new field of computer science.

The First Programmable Chip
When Kildall's draft notice for Vietnam arrived, he began training as a Naval officer. In 1969, the Navy tapped him to teach computer science at the Naval Postgraduate School in Monterey, California. There, he grew interested in the first programmable chip, and soon went to work for the microprocessor's manufacturer, Intel. Access to revolutionary hardware would spark Kildall to create revolutionary software.

Essential PC Software
Kildall's first effort was to create a programming language, PL/M, that could be used to write applications for microprocessors. Intel would use PL/M for decades. In 1973, Kildall wrote a software control program he called CP/M, which allowed files to be read and written to and from an eight inch floppy disk -- the first disk operating system for a microcomputer. Three years later, Kildall and his wife Dorothy formed a research and mail-order sales company, Intergalactic Digital Research, to design and market software for personal computers. Kildall rewrote CP/M to be usable on different types of computers, innovating a system called BIOS, or Basic Input/Output System. By 1978, the company was making $100,000 a month, and by 1983, revenues hit $44.6 million. For a time, Kildall's product would be the standard operating system on most PCs.

Little-Known Pioneer
Gary Kildall's name is not known today, and Bill Gates's is, because Gates's Microsoft Corporation produced an operating system that was a variant of CP/M, called QDOS. Microsoft licensed it to IBM as PC-DOS (and marketed its virtual clone, MS-DOS), using its business tactics to shut Kildall out. Still, Kildall continued to innovate. He created a multi-tasking version of his operating system that allowed users to do more than one task at once. He released an improved operating system, DR DOS, packed with features reviewers found lacking in Microsoft's offerings. Kildall even pioneered work on interactive videodisks and CD-ROMs, as well as PC networking software and wireless connectivity. In 1991, he sold his company to Novell for $120 million. While many of his software inventions went uncredited, Kildall remains a pathbreaker in the computer age. He died in 1994.